Heat exchange unit



March 3, 1936. B, s, FQSS HEAT EXCHANGE UNIT Filed March 23, 1935 l l I l i x 1 I l l I I I I l l I I |l I I I I I I I l I I I I I I I EN QN Patented Mar. 3, 1936 UNITED STATES aosasaz` nEAjr EXCHANGE UNIT Benjamin lS. Foss, Brookline, Mass., assignor to B. F. Sturtevant Company, Inc., Boston, Mass.

Application March 2,3, 1935, Serial No. 12,601

6 Claims.'

local recirculation units in each room, which rep ceive the conditioned air, mix it with recirculated air drawn in from the room and discharge the mixed air into the room. Since the conditioned air is supplied from the central source under pressure, it has been customary to pass the con-A ditioned air through injectors in the units to induce the flow of recirculated air. thus avoiding the necessity for a fan and driving motor in each unit.

Such units,l in the past, have not been completely lsatisfactory because of the ,fact thatV the mixed recirculated and conditioned air was not discharged from the unit at suiiiciently high velocity to obtain the correct distribution of the conditioned air within the space to be served; this probably because the injector air and recirculated air was permitted to expand in a diverging space between the injector and the discharge outlet. Another disadvantage of such units has been that it has been diillcult to properly adjust their controls in each room to obtain desired temperatures. f

According to this invention, a local recirculaf tion unit employs an injector through which con-V ditioned air is discharged to induce the ow of recirculated air. The conditioned air discharges into a restricted opening which extendsgall the way to the discharge outlet in the unit, into which is also drawn the induced ilow of recirculated air so that the mixed air/is discharged in a' concentrated jet which carries the mixed air to a considerable height above the unit with the result that in hot weather, the cold conditioned air may be carried in convection currents for substantially equal distribution throughout each room.

Other features of the present invention reside in an injector, the lips of which are not ad-` justed with respect to each other, as has beenl being discharged from the unit at high velocity.

by its action. The injector, in its adjustment, is caused to vary the position of a damper in the recirculated air passage, to decrease the amount of recirculated air available when the eiect of the injector upon the recirculated air is reduced and to make available an increased amount of recirculatedair as the injector is adjusted to be more eiective for inducing the flow of recirculated air. Thus the eiect of the injector uponthe drawing in of recirculated air is magnied through simultaneous adjustment of injector action, and of restrictions in the ow oi.' recirculated air to be acted upon by the injector. This is desirable because the recirculated air is drawn into the unit chiefly for the purpose of tempering with warm air from the room, the intensively conditioned air usually supplied by the central source.

An object of the -invention is to project condii tioned airfrom a local recirculation unit to asubstantial height above said unit.

Another object of the invention is to provide in a local recirculation unit, an injector supplied with conditioned air from a central source for inducing the flow of recirculated airrthe mixed air Another objectl of the invention is to control the effect of an injector in a local recirculation unit by varying the position of the injector nozzle with respect to the converging walls of a space into which it discharges.

Another object of the invention is to simultaneously adjust through a single control, the effect o f an injector for inducing the ow of recirculated air into a unit, and the quantity of recirculated air available to be acted upon by the injector.

Other objects of the invention will be apparent from the following description taken togetherv with the drawing.

` The invention will now be described with reference to the drawingof which:

Fig. 1 is a side sectional view of one embodiment of a local recirculation unit according to this invention, and

Fig. 2 is a side view. with a portion oi.' the cover 45 removed and a portion in dotted outline, of the unit of-Fig. l.

The unit is dened by the outer walls 5 and 5A which may be of metal or any other suitable mav terial. Supported within the unit is the coxn- 50 partment 6 into which is supplied through the duct i 2, conditioned air from a central source (not shown). The compartment is dened by the two vertical walls 1 and 1A, the lower horizontal wall and. the upperwall l0. which, how- 55 ever, contains an opening for receiving the injector nozzle II. l

The upper portion of the wall 1 is curved at I3 to provide, with the oppositely placed curved 5 wall I4, arestricted passagewith converging walls into which the tip I5 of the injector nozzle II, discharges. The nozzle I I is adapted to be moved up and down by movement of the gear I6 operated by the control knob I1, the gears I6, meshing with the teeth of the rack I8, with the vresult as the control knob I1 is rotated, the tip I5 of the nozzle moves nearer to or further away from the converging walls I3 and Il to increase or decrease, respectively, the effect of the injector action.

In the lower portion of the vertical wall 5A is provided the grille I 9 for the passage into the unit, of recirculated air. The horizontally placed grille 2li permits a-portion of recirculated air to pass into the recirculated air passage between the walls 5A and 1A. 'I'he damper 2l is provided in this passage to variably restrict the passage, under through the restricted opening in the tip I5 of l the nozzle I I at high velocity. 'I'he high velocity air discharging from the nozzle into the space between the converging walls I3 and I4 causes the inducing of recirculated air through the grilles I9 and 20. The conditioned air and recirculated air is mixed above thetip I5 of the nozzle and is discharged through the narrow slot 25 which extends all the way vto the top oi the unit. Ace cording to an important feature of this invention, the slot 25'is unconiined at its upper portion. Thus no back pressure is created by presence of any portion of the ordinary discharge grille with the result that the air passesat high velocity from the upper portion oi! the unit and completely to the ceiling of the room in which the lmit is placed. j y

The main reason for the inducing of recirculated air into a local recirculation air unit of this character is to permit, in summer, warm air from the room to increase the temperature of the cold air supplied from the central source. Air movement is not important since return air ducts from j each room exhaust air from the room which is ordinarily carried back to the centralsource of `\conditioned air 'to be reconditioned. Thus the exhaust of this 'air provides the n air movement. 1

By adjusting the effect of the injector, more or less recirculated air may be indrawn to warm more or less respectively the air passing through the unit. Thus, in the ordinary lmit, when the room becomes too cold the injector is adjusted to induce the flow of more recirculated air ior tempering purposes; likewise when the room becomes too warm the injector is adjusted so that less recirculated air is drawn into the unit.

According to this invention, the tempering effect of recirculated air is made use of to great advantage by controlling simultaneously the effect of the injector upon the recirculated air and the amount of recirculated air available for action thereon by the injector. y

Likewise when the air within the room becomes too cold and more recirculated air is re- I quired for tempering purposes, the knob I1 is manipulated to move the injector nozzle I I nearer the converging walls I3 and I4 for increasing the injector effect and simultaneously the damper 2| is adjusted to facilitate the flow of recirculated -air to be acted upon by the injector.

fore, in units of this type, the sole control of the A' iiow of recirculated air for tempering purposes was provided by adjusting the space between the Alips of an injector. Due to the ineiliciencies of injector arrangements, this'adjustment had too little eiect upon the inducing of recirculated air. Accordingly in prior units it was customary to pass the recirculated air through a heater which was operated to add heat to the recirculated air when the temperature Within a room became too cold.

The injector adjustment and the temperature adjustment may be, of course, separately controlled but it is preferred, for convenience 'of adjustment, that they be simultaneously adjusted.

Since the unit, according to this invention, is a universal one for supplying cooled air in summer, and heated air in Winter, the heating coils 21 are provided in the space between the vertical walls 5 and 1. When the steam or 'any other s uitable heating medium is supplied to the coil 21, recirculated air is drawn in through the grille I9, in

convection currents and is heated and discharged from a discharge grille 28, through openings on both sides of the slot 25, through which cool air s is supplied in'summer. Under unusual conditions the heating coil 21, could of course be used in summer to supply heated air to the room for tempering purposes simultaneously with the supply through the slot 25 of cold air. Such conditions may occur as when, due to a sudden drop in outdoor temperature, the operation of the central conditioning plant has not been correctly adjusted.

j vWhereas, one embodiment of the invention has been disclosed for the purpose of illustration, it should be understoodl that the invention 'is not limited to the exact arrangement disclosed as many departures may be made by those skilled in the art, after having had access to'this disclosure.

What is claimed is; 1. Heat exchange apparatus comprising a cas ing, means for admitting recirculated air from the space served byl said apparatus into said casing, means for admitting conditioned air into saidcasing, an injector within said casing so arranged with respect to saidmeans as to convert the pressure energy of the conditioned air into velocity energy and to induce the now of recirculated air into said casing, ,means forming a converging space into which said injector discharges, and means for mowing said injector into and out of said converging space for increasing and decreasing respectively, the effect of said 'injector upon the induced Ilow of recirculated casing, an injector within said casing so arranged with respect to said means as to convert the pressure energy of the conditioned air into velocity energy and to induce the flow of recirculated air into said casing, converging walls within said casing between which said injector discharges, and means for moving said injector into and out of the converging space between said walls for increasing and decreasing respectively, the effect of said injector upon the induced iiow of recirculated air. v

3. Heat exchange apparatus comprising a casing, means for admitting recirculated air from the space served by said apparatus into said casing, means for conducting conditioned air into said casing, an injector within said casing so arranged as to convert the pressure energy'of the conditioned air into Velocity energy so as to induce the flow of recirculated air into said casing, means for varying the effect of said injector upon the induced flow of recirculated air, and means for varying the quantity of recirculated air to be acted upon by said injector to increase the quantity of recirculated air when said injector is adjusted to be more `effective upon same and to decrease the quantity of recirculated air. when the injector is adjusted to be less effective upon same.

4. Heat exchange apparatus comprising a casing, an injector in said casing, means for supplying recirculated air from the space served by said apparatus into said casing, means for supplying a portion of the recirculated air supplied by said. means past the tip of said injector, means for supplying conditioned air through said injector to induce theiiow of recirculated air past its tip, means forming a converging space into which said injector discharges and a narrow pas-` sage extending to an outlet in said casing through which the mixed conditioned and reclrculated air is discharged from said casing in a concentrated jet, a heater in said casing, means for passing anand reclrculated air through said passage induces the ow of reclrculated air in contact with said heater.

5. Heat exchange apparatus comprising a casing, an injector in said casing, means for supplying reclrculated air from the space served by said apparatus, into said casing past the tip of said injector, means for supplying conditioned air through said injector to induce the ow of recirculated air, a discharge outlet in the'upper portion of said casing, means forming'a converging mentioned discharge outlet, means for supplying other recirculated air from the space served, through said casing and to said second outlet in a path exterior of but adjacent to said slot, whereby the air discharged from said rst mentioned outlet induces the flow of said other reclrculated air through said casing. 6. Heat exchange apparatus comprising a casing, an injector in said casing, means for supplying recirculated air from the space served by said apparatus, into said casing past the tip of said` injector, means for` supplying conditioned air through said injector to induce the flow of recirculated-air, means forming a converging space into which said injector discharges and a relatively narrow slot through which the mixed conditioned and reclrculated air is discharged in a concentrated jet, means for supplying other recirculated air from the space served, through said casing in a path exterior of but adjacent to said slot, whereby the air discharged from said slot induces the iiow of said other reclrculated air through said casing, and means in the upper portion of said casing for the discharge therefrom of the air passing therethrough.

' BENJAMIN S. FOSS. 

